"Air quality standards are supposed to offer equal protection to all, but the poor are not enjoying the same level of protection as others," Gordon Mitchell of the University of Leeds, UK, told environmentalresearchweb. "Our results show that the poorest neighbourhoods in Britain continue to bear a disproportionate and growing share of poor air quality, which means that the health impact will disproportionately fall on the poor too."

Mitchell and colleagues from the University of Leeds used ten years’ worth of air quality and social data in Britain, from 2001–2011, to look at two pollutants responsible for premature deaths – fine particulates known as PM10s and the toxic gas nitrogen dioxide (NO2). Air quality improved over this period, but it is estimated that there are currently about 29,000 premature deaths a year in the UK due to fine particulates, whereas NO2 is responsible for 23,500 deaths per year.

"Our work provides the first national, small-area analysis of how air quality is distributed ‘socially’ over time," said Mitchell. "Describing this change over time helps us understand what influences the unequal distribution of air quality, and whether policymakers need to do something about it."

The researchers found that the annual average of NO2 has fallen significantly, but the rate of improvement has been slower for poorer areas. Nearly all the wealthiest areas no longer exceeded the NO2 concentration limits of the EC standards, but 70% of the poorest did. On the other hand, PM10 increased because of further car pollution, affecting poor neighbourhoods more quickly. Of the millions of people exposed to PM10 concentrations above the World Health Organisation (WHO) annual guideline, 58% were in the most deprived areas, accounting for 20% of the population.

"Our analysis shows that whilst environmental quality has improved, environmental inequality and injustice has increased," said Mitchell. "Most environmental justice advocates assume that higher environmental quality is fully compatible with social justice, but our study demonstrates that these two objectives may not always be met simultaneously."

According to Mitchell, the findings will also be helpful in explaining health inequalities, for example why some areas have higher levels of disease than others. "We anticipate that disease burden due to NO2 will have declined since 2001 and increased for PM10," he said. "The total disease burden is likely to have fallen, but more slowly in poor populations."

The researchers now plan to investigate air quality in Britain at a city region level. "We are going to delve deeper into our data to find out whether there are city regions that have higher levels of environmental inequality than others, how fast it is changing, and why," Mitchell said. "Is this inequality driven by a changing environment, such as environmental policy or plans, or is it caused by a changing population?"

Mitchell and colleagues published their work in Environmental Research Letters (ERL) in the ERL Focus on Environmental Justice: New Directions in International Research.

Related links

Related stories